1. Field of the Invention
The present invention relates to a wired perimeter burglar alarm system and to an adapter for use in conjunction with a push-button type switch incorporated into the circuit of the system, the adapter functioning to permit the push-button switch to extend to an alarm-actuating position upon an unauthorized entry through a door and to remain in that alarm-actuating position upon reclosing the door.
2. The Prior Art
There are two major categories of burglar alarm systems: perimeter protectors and motion detectors. Each type of system has its own advantages and disadvantages. Motion detectors employ an energy transmitter and receiver to establish an energy path which is broken by an object passing therethrough, resulting in the sounding of some form of alarm. Motion detectors utilizing visible light, ultrasonic energy, infrared radiation and microwave have all been marketed. They offer the advantage that they are simply installed without the necessity of wiring but they also have serious shortcomings in that they allow a burglar to enter inside a home before sounding the alarm and are easily inadvertently triggered by the movement of pets. Once activated, they restrict movement of the homeowner's family within the home.
The significant disadvantage of the perimeter wired system is its cost and difficulty of installation. The most costly component of a perimeter wired system is the control module. One function of the control module is to maintain the sounding of an alarm once the perimeter is violated. In other words, when the perimeter is violated in such a way that a switch in the alarm system circuit is, for example, opened in the case of a normally closed circuit, the alarm cannot be quieted simply by reclosing the switch, as by reclosing a door through which entry was obtained--the control module functions to maintain the alarm, once tripped, until the control module is properly reset.